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ABR on A BABY!

Check out this crazy snowstorm we had last night and the terrible phone pictures I captured it with:
We got pounded yesterday evening, and though I am not a fan of snow, it was so pretty! Hopefully it will go away soon.

We had a lot of cancellations in the clinic today due to the weather (many of our patients are elderly), but luckily mine showed up. My first patient was a baby–hardly 4 weeks old! I’ve mentioned testing subjects for AEP class a few times. Remember Ryan and the electrodes? Well that’s one way to test hearing with babies.

Babies can’t raise their hands when they “hear the beep,” so we need to test them in a way that doesn’t require a response. In auditory brainstem response (ABR) testing, we put an itty bitty insert earphone in the baby’s ear that plays clicks or short tonebursts repeatedly, and we stick little electrodes to their head. As the click or toneburst sound travels from the earphone through their auditory system, the system creates tiny electrical fields that are picked up by the electrodes and can be measured on the computer. We make the sounds quieter and quieter until we reach normal limits or until there is no measurable response.

We start with clicks instead of tone bursts because they have a clearer and more robust waveform response. The downfall of clicks is that they don’t get frequency specific information. That is, clicks don’t tell us how well you hear high sounds vs low sounds. Hearing loss doesn’t usually mean a flat decrease in hearing over all frequencies; many times high-pitched sounds are more affected than low-pitched sounds, so it’s important to figure out how much hearing loss a patient has as a function of frequency in order to amplify them properly (i.e. program the hearing aid to their specific type of loss).

This was my very first time seeing an ABR on an infant, and it was very exciting. This little baby’s results indicated normal hearing.

Testing on a baby is extremely different from testing on my lab partners. Mostly because my lab partners can stay quiet and sit still for an hour if I ask nicely (and bribe them with chocolate). Babies, not so much.